May 12, 2013 2:04 PM

2 days ago I went for a 50min easy run. The next day I woke up with a pain under my foot around the bottom of the 5th metatarsal. I only hurts when I walk and pain is low-moderate but I don't want it getting worse. I can run and hop without pain so am hoping/thinking it isn't a stress fracture. any ideas? do you think I can keep running? thanks

If your location of pain is that specific, and you have ruled out blisters, rocks in shoes, etc. it is more likely to be a stress fracture than something insignificant. You may also have strained a ligament or encountered some form of metarsalgia. I know of no myofascial pain patterns that confine themselves to so small a spot, but there is the possibility of a neuroma in that location, which may get your bones off the hook, but can be tough to manage.

I'm going to take a wild guess that you have high arches, which divert more pressure onto the smaller 4th & 5th metatarsals, which obviously break more easily. Maybe you pronate a bit more when running to absorb shock, taking some of the direct pressure off these slender bones. Either way, unless you suddenly picked up your mileage, or provided some other unusual stress, there probably is something wrong down there that needs to heal right. I'd stay off it if I were you, and if gentle ambulation still hurts, you may have to shell out for an exam.

Meanwhile, a look at your shoes is required to see if anything has gone wrong there. Do you feel pain in all footwear? Or, just when walking in the running shoes? Were there any recent equipment changes, or changes to the running surface? Are you using a treadmill? How long have you been running?

I feel most pain walking barefoot/casual shoes, much less walking in running shoes. I have been running for 8 years but recently have had 6 months off due to ITBS so began running again 2-3 months ago am at pretty long milage 30km/wk at the moment. If it was a stress fracture why wouldn't it hurt a lot hoping/running? I t seems to hurt most the day after a run upon waking. Yes I think I have high arches and was running in new shoes on grass, but switching back to my old shoes didn't help.

I thought maybe it could be Peroneal Tendonitis but the symptoms don't exactly fit as my pain is not at the ankle.

The best place to start in search of a solution, is to get a professional look at your biomechanics. Even if you had some need to overpronate your foot, another adaptation to foot instability or pain might be to oversupinate, which would put much more pressure on your 4th and 5th metatarsals during repetitive (sustainable) motion. Your biomechanics for hopping or running may be quite different.

Stress fractures are a possibility whenever there is too much stress on a part of your anatomy not designed for it. If you had six months off, and plunged back into 18-mile+ weeks, you could be just as vulnerable to damage as you were before the long layoff. You had rest and recovery, but lack of conditioning as well. You need to make a gradual comeback after 6 months off, planning about a year to get back to where you were.

Back to a stress fracture, it's not the only possibility, but what can happen when an unconditioned part of your anatomy is subject to repetitive stress. Tendon pulling the periosteum, or the "skin" of your bone, off the bone as a result of repeated use, is an example of a type of stress fracture called an avulsion fracture. It's not like a simple fracture where the entire bone is cracked, or necessarily in danger of breaking completely, but does weaken the bone's integrity. In the case of an average stress fracture, it does not happen all at once, but is a gradual weakening process. Similar things happen in aircraft or other machinery subjected to repeated stress, except that you as a human can feel the pain of it coming on. In addition to forms of tendinitis, periostitis can present before actual separation occurs. Great to have these early warning signs.

I believe though, that you may be supinating to avoid pressure on the rest of the foot, at least during a walk. This would focus pressure down there, and eventually would hurt during a slow, weight-bearing process like walking. As Freud used to say, sometimes a cigar is just a cigar. What I was trying to say before, is that your biomechanics when running or hopping could be quite different, not putting the same stress on the same places. A treadmill analysis of your gait while running or walking could reveal this. In that case, it needs to be determined what structural or muscular insufficiency you may be compensating for, and to attack this problem from the angle of reducing the need for the kind of biomechanical overcompensation that overwhelms your anatomy.